WO2004029393A1 - Vehicle security system and wireless key having wireless authentication function applied thereto - Google Patents

Abstract

A vehicle security system for reducing power consumption of a battery in a vehicle and a wireless key. The vehicle security system comprises a vehicle control means provided on the vehicle side for searching a trigger pulse signal at a predetermined time interval and performing a predetermined control operation to the vehicle, and the wireless key for generating the trigger signal. The wireless key comprises a means of generating and transmitting the trigger pulse signals of a predetermined number when a key body is oscillated, and a means for receiving an identification signal in response to the trigger pulse signal from the vehicle, adding the identification signal of the wireless key to the trigger pulse signal, and transmitting it to the vehicle when the identification signal is matched with a predetermined signal.

Description

 Specification

TECHNICAL FIELD The present invention relates to a vehicle security system and a wireless key having a wireless authentication function applied thereto.

 The present invention relates to a vehicle security system and a vehicle key having a wireless authentication function applied thereto. BACKGROUND ART In recent years, improvements have been actively made to enhance the convenience for drivers and passengers of passenger vehicles. As one of them, a wireless key system that controls opening and closing of a vehicle door by non-contact communication between a key and the vehicle has been introduced.

 One form of such a wireless key system is a one-way communication system that emits an infrared signal or a radio signal from a key held by a user and opens and closes a door when a control means provided on the vehicle detects the signal. There is a system.

 On the other hand, there is a two-way communication system that controls the opening and closing of doors by issuing signals from both directions on the vehicle side and the key side of the user and performing mutual authentication. In a conventional example of a wireless key system using such a two-way communication system, a device mounted on a vehicle continuously performs an operation of detecting a signal emitted from the wireless key.

 That is, in the conventional system, an inquiry signal is constantly transmitted to both the vehicle side and the wireless key side in order to detect the timing at which the signal can be exchanged with the wireless key continuously while the vehicle is in progress and while the vehicle is parked. Is necessary.

In such a configuration, it is necessary to constantly transmit the inquiry signal from the on-board equipment of the vehicle and from the wireless key side, and therefore the battery consumption of the vehicle and the wireless key must be large. Did not. Disclosure of the invention

 Accordingly, it is an object of the present invention to provide a vehicle security system that reduces battery consumption in such vehicles and wireless keys.

 At the same time, it is an object of the present invention to provide a vehicle security system capable of ensuring a high degree of security and a vehicle key having a wireless authentication function applied thereto.

 A first aspect of the vehicle security system according to the present invention that achieves the above object is a wireless key that generates a key transmission pulse, and is provided on the vehicle side, searches for the key transmission pulse at a predetermined cycle, and And vehicle control means for performing predetermined control on the vehicle when authentication is established between the wireless key and the wireless key. The wireless key generates and transmits a predetermined number of the key transmission pulses when there is vibration with respect to the key body. Receiving an identification signal in response to the key transmission pulse from the vehicle side, and adding the identification signal of the wireless key to the key transmission pulse when the identification signal matches a predetermined signal. Means for transmitting to the vehicle. According to a second aspect of the vehicle security system according to the present invention that achieves the above object, in the first aspect, a time period for searching for a key transmission pulse by the vehicle control means, a period for searching for the key transmission pulse, and Is characterized in that the duty ratio is 1/10.

 According to a third aspect of the vehicle security system according to the present invention that achieves the above-mentioned object, in the first aspect, the vehicle control means includes: when the identification signal of the wireless key is a predetermined identification signal; It is characterized in that predetermined control is possible.

 Further, a fourth aspect of the vehicle security system according to the present invention that achieves the above object is, in the third aspect, characterized in that the predetermined control for the vehicle is a control for opening and closing a door of the vehicle. I do.

A fifth aspect of the vehicle security system according to the present invention that achieves the above objects. According to a fourth aspect, in the fourth aspect, the predetermined control for the vehicle includes a control for enabling or disabling an engine start of the vehicle.

 A sixth aspect of the vehicle security system according to the present invention that achieves the above object is a wireless key that generates a key transmission pulse, a plurality of detection means provided on the vehicle side for detecting the key transmission pulse, A key transmission path, which is provided on the vehicle side and is detected by any of the plurality of detection means, is searched at a predetermined cycle, and when authentication with the wireless key is established, predetermined control is performed on the vehicle. Vehicle control means for performing the key transmission pulses when the key body is vibrated, and generating and transmitting a predetermined number of the key transmission pulses; and responding to the key transmission pulses from the vehicle side. Receiving the identification signal, and when the identification signal matches a predetermined signal, adds the identification signal of the wireless key to the key transmission pulse and transmits the key to the vehicle. Means.

 A first aspect of the wireless key according to the present invention that achieves the above object is to form a vehicle security system with a vehicle having vehicle control means for searching for a key transmission pulse at a predetermined period and performing a predetermined control operation. A vibration sensor that turns on a key trigger when there is a vibration to the key body, and generates a predetermined number of key transmission pulses when the key trigger from the vibration sensor is on. Means for transmitting to the vehicle side; and receiving an identification signal responsive to the key transmission pulse from the vehicle side, and adding the identification signal of the key body to the trigger pulse signal when the identification signal matches a predetermined signal. Means for transmitting to the vehicle.

 According to a second aspect of the wireless key according to the present invention that achieves the above object, in the wireless key according to the first aspect, power for driving the key body is supplied by a button battery.

Furthermore, a third aspect of the wireless key according to the present invention that achieves the above object is the wireless key according to the first aspect, wherein the vibration sensor includes: It consists of a mercury switch that is closed by the movement of the key holder.

 A fourth aspect of the wireless key according to the present invention that achieves the above object is the wireless key according to the first aspect, wherein at least one key is set within a time period in which the vehicle control means searches for a key transmission pulse. The number of key transmission pulses transmitted when the key trigger is turned on is set so that transmission pulses are detected.

 The features of the present invention will become more apparent from embodiments described below with reference to the drawings. BRIEF DESCRIPTION OF THE FIGURES

 FIG. 1 is a diagram illustrating a vehicle security system to which the present invention is applied.

 FIG. 2 is a diagram showing an example in which the vehicle security system shown in FIG. 1 displays on a monitor a state in which a door is locked and a state in which an immobilizer control for disabling engine starting is turned on.

 FIG. 3 is a configuration example of a wireless key to which the present invention is applied.

 FIG. 4 is a block diagram of a detailed configuration example of a main control circuit block of the wireless key.

 FIG. 5 shows a time chart of one embodiment in the search mode (when not riding).

 FIG. 6 shows a time chart of one embodiment during boarding.

 FIG. 7 is a block diagram showing a detailed configuration example of the integrated circuit chip 100. As shown in FIG.

 FIG. 8 is a diagram showing a configuration of an embodiment of a main part of the vehicle control means on the vehicle 3 side related to the present invention.

 FIG. 9 is a diagram illustrating an M-sequence signal.

FIG. 10 is a diagram illustrating a configuration example of the pulse compression processing in the coincidence / addition circuit. FIG. 11 is a diagram illustrating the identification signal transmission timing and the response signal reception timing.

 FIG. 12 is a diagram illustrating the determination of the signal level.

 FIG. 13 is a diagram illustrating a change in the received signal level depending on the distance. FIG. 14 shows an embodiment in which a plurality of doors are individually controlled using the wireless key 1 of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

 An embodiment of the present invention will be described below with reference to the drawings.

 FIG. 1 is a diagram illustrating a vehicle security system to which the present invention is applied. In FIG. 1, two-way communication is performed between a wireless key 1 possessed by a user 2 and a vehicle 3 to be secured, which is a feature of the present invention.

 In such two-way communication, the wireless key 1 detects that the distance from the vehicle is within a predetermined interval or exceeds a predetermined interval. In addition, authentication is performed between the vehicle 3 and the wireless key 1, and based on this, control such as opening and closing of a door is performed by control means provided in the vehicle 3.

 FIG. 2 shows an immobilizer control that disables vehicle 3 engine starting when the door of vehicle 3 is locked as a result of two-way communication between wireless key 1 and vehicle 3 in FIG. The state in which is set to ON is shown on the monitor 10. Thus, the user 2 can easily confirm the security state when the vehicle 3 is parked.

 FIG. 3 is a configuration example of a wireless key 1 to which the present invention is applied. FIG. 3A is a conceptual perspective view of the wireless key 1 when viewed from the surface. FIG. 3B is a perspective conceptual diagram when viewed from the side.

As an example, the wireless key 1 has a force shape with a width W, a thickness, and a length L, but may have an appropriate shape. In FIG. 3, the main control circuit block 100 can be constituted by one integrated circuit chip. Battery 101, ON / OFF switch 102, peripheral parts A display panel 103 such as a liquid crystal display, an EL display, and the like are further provided with a vibration sensor 104 for detecting a movement vibration of the wireless key 1 as a feature of the present invention, and are integrally molded in a card shape.

 In FIG. 3, the emergency spare key 105 is configured to be inserted into the card.

 FIG. 4 is a block diagram showing a detailed configuration example of the main control circuit block 100. In the main control circuit block 100, an antenna element 106 not shown in FIG. 3 is connected to the transmission circuit 110 and the reception circuit 111 through the branch circuit 107. Further, the main control circuit block 100 includes a timer 112, a power control circuit 113, and a control circuit 114. The power control circuit 113 is supplied with electric power from the battery 101, and the components of the main control circuit block 100 are supplied with power at the required time under the control of the power control circuit 113. You.

 An ON / OFF switch 102 and a vibration sensor 104 serving as a trigger switch are connected to the power control circuit 113 as external elements of the main control circuit block 100.

 The power control circuit 113 sets the control circuit according to the timing of the signal from the ON / OFF switch 102 and the vibration sensor 104, using the timing counted by the timer 112 as a reference clock. Drive 1 1 4

 The control circuit 114 controls the signal transmission from the transmission circuit 110 to the vehicle control means mounted on the vehicle 3 and receives and controls the response signal through the reception circuit 111 from the vehicle control means.

 The control circuit 114 further has a function of controlling the display of the control result on the display panel 103.

Here, in connection with the subject of the present invention, the power consumption of the vehicle control means disposed on the vehicle 3 side and the wireless key 1 when configuring the vehicle security system will be examined. In order to realize a vehicle security system, the average permissible current consumption on the vehicle 3 side is specified by the Japan Industrial Association as a vehicle standard of 1 mA. On the other hand, it is desirable that a trial period of about three years can be obtained by using a button type CR203 as the battery 101 used for the wireless key1.

 Furthermore, it is assumed that the peak current on the vehicle side during security operation requires 10 mA. Based on these conditions, the operation duty of the vehicle control means disposed on the vehicle 3 side is assumed to be 1/10 and will be discussed below with reference to the time charts of FIGS.

 FIG. 5 shows a time chart of the embodiment in the search mode (when not riding). As described above, the reaction operation control period in the vehicle control means arranged on the vehicle 3 side is assumed to be 25 ms, and the operation cycle of the receiver of the vehicle control means (hereinafter simply referred to as the base receiver) is set to 250 ms. Then, a duty ratio of 1/10 is obtained (see Fig. 5a). As a result, even if the peak current required for the reaction operation control on the vehicle side is 10 mA, it is possible to conform to the vehicle standard where the average allowable current consumption is 1 mA.

 On the other hand, the vibration sensor 104 of the wireless key 1 can be constituted by, for example, a mercury switch or the like, and can generate a trigger signal in response to a predetermined size of movement of a person holding the wireless key 1. Yes (see Figure 5b). The power control circuit 113 drives the control circuit 114 during a predetermined period counted by the transmission / reception control timer 112 based on the trigger signal, and sends a key transmission pulse to the transmission circuit 110. Power is supplied so that transmission is possible.

 At this time, the control circuit 114 sets a predetermined number of key transmission pulses so that at least one key transmission pulse can be received during the operation period (25 ms) of the pace receiver operation period of 250 ms. In the embodiment of FIG. 5, control is performed so as to transmit 20 key transmission pulses at a period of 12.5 ms (see FIG. 5C).

 FIG. 5d is an expanded view of the key transmission pulse (FIG. 5c) during the operation period of the base receiver (25 ms). The pulse width of one key transmission pulse has a size of 1.5 ms, and a spreading code (M string: Maximum length sequence signal) is used to identify each wireless key. Is completed.

The base receiver receives a key transmission pulse during its operating period (25 ms). In response, the identification signal ID of the vehicle control means of the vehicle 3 is added, and a base response transmission pulse is transmitted from the transmission circuit 110 through the antenna 106 (see FIG. 5e).

 The wireless key 1 enters the standby state during the key transmission pulse width during the key transmission pulse transmission period (see Fig. 5f). If there is no response from the pace receiver during this standby period, power is not supplied to the receiving circuit 111 until the next standby state timing in the wireless key 1 o

 On the other hand, when the identification signal ID in the response signal from the base receiver is detected during the standby period, the same identification signal ID is transmitted as an M-sequence signal (see Figs. 5g and 5d). Thus, the correspondence between the wireless key 1 and the vehicle 3 can be established in the vehicle control means.

 Based on the establishment of this correspondence, various controls of the vehicle can be performed based on the control signal from the vehicle control means of the vehicle 3. For example, if the door of the vehicle 3 is in the open state, the state is shifted to the locked state, and if the door is in the locked state, the state is controlled to shift to the open state.

 Here, the opening / closing control of the door is automatically performed on the condition that the correspondence between the wireless key 1 and the vehicle control means of the vehicle 3 is established on the vehicle 3 side, or on the condition that the correspondence is established. Furthermore, it is possible to control the wireless key 1 in response to pressing of the ON / OFF switch 102 by the holder.

 At the same time, if it has immobilizer function, wireless key 1 and vehicle

When the correspondence between the three vehicle control means is established, control is performed by the vehicle control means so that the engine can be started.

Here, according to the experiment of the inventor, when the wireless key 1 is held and a normal activity is performed, the state in which the key trigger in the wireless key 1 is turned on (see FIG. 5B) is one day. The average was 300 times. In addition, the key transmission pulse when the key trigger becomes ◦N once is 20 transmissions with a pulse width of 1.5 ms. Therefore, the cumulative transmission time of the day is 9 seconds (0.0 0 25 Time).

 Assuming that the current peak value of one key transmission pulse is 14 mA, the daily transmission current-time product is 0.035 (= 14 * 0.02 5). Furthermore, the dark current in the standby state (see Fig. 5f) is about 3A.

 Therefore, since the current capacity of the button battery of CR 2 0 3 2 is 220 mA H, the battery life is 205 6 days [= 2 0 0 / (0.0 3 5 + 0.0 0 0

3 * 2 4)] That is, it is 5.6 years.

 The above calculations are the battery life characteristics when the vehicle is not in use. On the other hand, in general, the wireless key 1 is held even when the vehicle 3 gets on. At this time, as shown in FIG. 6, communication between the wireless key 1 and the control means of the vehicle 3 is performed by a handshake.

 The reception interpal of wireless key 1 during handshake is set to 2 seconds (see Fig. 6a), and the transmission / reception gate time is set to 10ms (see Fig. 6c). In addition, the average ride time is 3 hours. Therefore, under this condition, the key receiving operation time when the wireless key 11 is on board is 0.015 (= 0.010 / 2 * 3) per day. Assuming that the peak current of key reception is 6 mA, the reception current time product is 0.090 mAH per day (= 0.015 * 6).

 Considering the product of the reception current and time of the wireless key 1 during such a ride, the battery life is 1 1 1 7 days [= 2 2 0 / (0.0 3 5 + 0.0 3 * 2

4 + 0.09 0)] That is, about 3.1 years.

 Therefore, the wireless key 1 according to the present invention applied to the vehicle security system can use a general button battery and obtain a service period exceeding 3 years in practical use.

 Here, as an embodiment, a specific configuration example of the integrated circuit chip 100 of the wireless key 1 and a specific configuration example of the vehicle control means mounted on the vehicle 3 will be described.

FIG. 7 is a block diagram showing a detailed configuration example of the integrated circuit chip 100. In Fig. 7, the connection with peripheral elements is partially omitted from the relationship with Fig. 4. Is shown. The transmission circuit 110 has a transmitter 110 b for transmitting an identification signal including a preset unique code signal from a transmission antenna 106 T, and the reception circuit 111 is provided on the vehicle 3 side. And a receiver 111a for receiving, via a receiving antenna 106R, an acknowledgment signal returned from the transmitter of the vehicle control means.

 The transmission circuit 110 converts the identification signal set in the identification code memory 114 d in the control circuit 114 into an M-sequence signal based on the evening output of the transmission / reception control timer 112. After the FSK modulation circuit 110a performs FSK modulation with a carrier, the transmitter 110b transmits the key transmission pulse (see FIG. 5d) described above with reference to FIG.

 The power control circuit 1 13 a of the power control circuit 113 closes the switch 113 b at the output timing of the transmission / reception control timer 112 to supply power from the battery 101 to each part. Control.

 On the other hand, the receiving circuit 111 that receives the base response transmission pulse (see Fig. 5e) includes a receiver 111a and the following components and is connected to the receiver. The received base response transmission pulse is subjected to FSK demodulation by the three demodulation circuits 111b and sent to the matching and adding circuit 114c in the control circuit 114.

 The match / addition circuit 114c reads the identification signal stored in advance in the identification code memory 114d, and the identification signal transmitted from the vehicle 3 by the base response transmission pulse is used as the identification code. It is determined whether or not it matches the identification signal stored in the memory 114d. For this purpose, the match-addition circuit 114c performs a process of adding a match point for each bit of the identification signal. The output signal subjected to the addition processing is supplied to the threshold processing section 114f.

 The threshold processing unit 114f compares the output signal from the match / addition circuit 114c with a threshold (threshold value) preset in the threshold setting unit 114e, and outputs the output signal. If the value exceeds the threshold, the timing signal is sent to the signal presence / absence determination unit 1 1 4b.

On the other hand, the identification signal received by the receiver 1 Also sent to 1 1 4a. Then, a signal representing the signal level detected by the signal level detection circuit 114a is sent to the signal presence / absence determination section 114b. The identification signal from the FSK demodulation circuit 111b and the identification code signal from the identification code memory 114d are also input to the signal presence / absence determination section 114b.

 The signal presence / absence determination unit 114b determines whether the base response transmission pulse (Fig. 5e) matches the discrimination code signal, and outputs the timing signal from the threshold processing unit 114f. After receiving the signal, it is determined whether the signal level of the identification signal of the base response transmission pulse received within a predetermined time is equal to or higher than a predetermined value. The signal presence / absence determination unit 114b adds the wireless key 1's own identification signal to the key transmission pulse and transmits it to the vehicle 3 when both of these two determinations are satisfied (see Fig. 5d). In particular, it controls the reading of the identification signal from the identification code memory 114d.

 FIG. 8 shows an embodiment of a main part of the vehicle control means of the vehicle 3 related to the present invention. This vehicle control means is substantially the same as the structure of the integrated circuit chip 100 of the wireless key 1 shown in FIG. 7, but is slightly different in some respects. Hereinafter, the different parts will be mainly described.

 The signal presence / absence determination section 302b determines whether or not the signal sent from the wireless key 1 is present. When the key transmission pulse of the M-sequence signal (see FIG. 5e) is received, the identification code memory 3 By accessing 02b, the identification signal ID stored in the vehicle 3 is transmitted as a base response transmission pulse to the wireless key 1 by the transmission circuit 305 (FIG. 5e).

 On the other hand, the opening / closing control signal generating section 303 determines whether or not the wireless key 1 matches the identification signal of the wireless key 1 added to the key transmission pulse from the wireless key 1 (see FIG. 5d) by the signal presence / absence determining section 302 b. When it is detected, an open / close control signal is generated and used for controlling the opening / closing of the vehicle door. Such a point has no direct relation to the features of the present invention, and further description is omitted.

In addition, the power of the power supply section 304 is controlled by the transmission / reception control timer 303 so that it operates during the periodical ON period of the pace receiver shown in FIG. As described above, the signals are supplied to the corresponding circuit components. Thereby, in connection with the object of the present invention, it is possible to reduce the power consumption also on the vehicle 3 side.

 Here, in the description of the above components, the identification signal from the wireless key 1 (see FIG. 5d) is a signal including a preset unique code signal, and this identification signal is an M-sequence (Maximum length). null key) signal followed by a unique code signal for wireless key 1 (hereinafter simply referred to as a unique code signal).

 The M sequence signal may be a C / A code, a P code, a linear FM signal, or the like. Further, the unique code signal may be a signal indicating information of the owner and the manager.

The M-sequence signal is a kind of binary pseudo-random signal, and has a length obtained by subtracting 1 from 2 n, that is, a code string composed of 1s and 0s having a length of ( ²ⁿ -l) —D), for example, if n = 5, it is a 31-bit signal. When this M-sequence signal is sent to the coincidence / addition circuit 114c (FIG. 7), a pulse compression signal B is obtained as shown in FIG. 9 for explaining the M-sequence signal. In this pulse compression, the M-sequence signal, which is the input signal, is subjected to 1/31 signal compression.

Here, the above unique code signal needs to be sold for the number of wireless keys 1, but if the code length is m bits, 2 ^m types are possible.For example, if m = 30 About 100 billion unique code signals are possible. As described above, the identification signal ID is transmitted from the vehicle control means and received by the wireless key 1 (see FIG. 5e). Based on this, the same signal is added to the key transmission pulse as a confirmation identification signal ID after a lapse of a certain time from the wireless key 1 and sent back to the vehicle 3 (see Fig. 5d).

 It is necessary to determine whether the identification signals ID match or not, and FIG. 10 shows a configuration example of the pulse compression processing in the matching and adding circuit 114c of the key 1. The same applies to the operation of the coincidence / addition circuit 302c on the vehicle 3 side in FIG.

When the received signal is demodulated by the FSK demodulation circuit 111b, the leading M-sequence signal is temporarily recorded in the shift register 111c, not shown in Fig. 7. Remembered.

 The M-sequence signal written to this shift register 111c is sent to the matching / addition circuit 114c, where the M-sequence signal is stored in the identification code memory 114d. Is called, and it is compared whether both M-sequence signals match for each bit, and the number of matching bits is added.o

 The signal that has been subjected to the “matching” addition processing is output as a pulse compression signal. In this example, the shift register 111c has a storage capacity of 31 bits, but the identification code memory 114d has an M-sequence signal (31 bits) and a unique code signal (29 bits). ), And has a storage capacity of 60 bits. Therefore, when processing both of the M-sequence signals, the data portion of the M-sequence signal is called.

 The operation of the embodiment having the above configuration will be described below by dividing the operation into the wireless key 1 and the operation on the vehicle 3 side.

 First, when transmitting an identification signal from the wireless key 1, a vibration sensor 104 (not shown) detects the vibration of the wireless key 1 and immediately sets the transmission / reception control timer 112. This closes the switch 113b through the power control circuit 113a at each key transmission pulse time point (see Fig. 5c), and power is supplied from the battery 101 to each part.

 Here, referring to FIG. 11, as shown in the time chart (a), at the timing (b) at which the switch 113b becomes 0 N, the identification code memory 1 is issued by the instruction of the control timer 13a. The identification signal ID is read from 14b, modulated by the FSK modulation circuit 110a, and then transmitted from the transmitter 110b via the transmission antenna 106T.

As described above, the transmission of the identification signal ID is performed by FSK-modulating the 31-bit M-sequence signal and the subsequent 29-bit unique code signal. If the transmission signal of the identification signal from the wireless key 1 is received at a predetermined level or more by the vehicle control means of the vehicle 3 and the identification signal is recognized by the vehicle 3 to be its own, the vehicle control is performed. The above identification signal The same transmitted signal as the signal is sent back to the wireless key 1 and received as a confirmation signal (Fig. 5d) o

 The transmission and reception timings are as shown in (a) and (c) of FIG. Switch 1 13b of wireless key 1 is activated (T ims) + transmission (T 2 ms) + lag time (T 3 ms) + response reception (T 2 ms) + lag time (T 3 ms) = T The state is set to 0 N for l + 2 (T2 + T3). Power is supplied from the battery 101 during this 0 N period.

 After that, when the switch 113b of the wireless key 1 is set to 0 N at a fixed period of, for example, 12.5 ms after the first switch 113b is turned on, the transmission timing is controlled by the control timer 13a. Is controlled.

 On the other hand, when the base response transmission pulse sent back from the vehicle 2 at a predetermined timing is received by the receiver 111a, it is demodulated by the FSK demodulation circuit 111b and then matched and added. Pulse compression processing is performed at 14c. This has already been described with reference to FIG.

 In this pulse compression processing, among the confirmation signals, the M-sequence signal of symbol A shown in Fig. 9 (a) is subjected to pulse compression processing, but the signal subjected to coincidence and addition processing is shifted as shown by symbol B. Before or after the pulse train of the M-sequence signal is completely written to 1c, the data of each bit is stored in the M-sequence signal storage data of the identification code memory. , The value of the pulse compression signal always fluctuates. However, if the data coincident with the M-sequence signal stored in the self-identification code memory 114d is written to the shift register 111c, the match-addition circuit 114c performs the coincidence addition processing. If the number of bits to be converted is satisfied for all bits 31 of the shift register 1 1 1 c, the pulse compression signal becomes 31 and the M-sequence signal is a perfect match or at least a match. If the number of signals is 24 or more, both M-sequence signals can be regarded as coincident.

Therefore, the threshold processing unit 114f sets the pulse compression processing signal to a threshold (threshold value) preset by the threshold setting unit 114e, for example, 24 or more. Is determined (see FIG. 9 (b)). When the threshold processing section 114d determines that the pulse compression processing signal exceeds the threshold, it outputs a timing signal as shown in FIG. 9 (c) to the signal presence / absence determination section 114b.

 As described above, the signal level detection circuit 114a detects the signal level of the received signal received by the receiver 111a. The signal presence / absence determining unit 114b determines whether or not the signal level is equal to or higher than a predetermined value. This signal level is determined by setting a certain voltage threshold for the received signal with the detection waveform shown in Fig. 12 (see Fig. 12a). If so, it is determined that a signal of a certain level or more has been received. As shown in Fig. 13 (a), when the signal R transmitted at a certain strength is received and the distance R between the wireless key 1 and the vehicle 3 increases, the above determination is made as the square of the distance. It is based on the fact that the received signal level decreases in inverse proportion. As one of the determination methods, the above-mentioned threshold value is determined corresponding to a predetermined distance (for example, lm).

 If the received signal level falls below the threshold, it is detected that both have been separated by more than a predetermined distance. Fig. 13 (a) is shown on a logarithmic scale. Instead of this determination method, the level of the received signal may be known by AZD converting the detection waveform of the received signal and measuring the voltage level of the received signal.

 The determination of the signal level is based on a certain time t (corresponding to the eigencode signal to be received later) in which the timing signal after the threshold processing for the M-sequence signal is transmitted from the threshold processing unit 302f. In the example, it is performed only for 1.5 ms). The reason is that noise and signal levels from other wireless keys are not detected, and the judgment can be made accurately by using the fixed time specified by the evening signal as the judgment section. It is.

The determination by the signal presence / absence determination section 302 b is performed in addition to the determination of the signal level described above, in which the unique code signal received after the evening timing signal is input and FSK modulated is stored in the identification code memory 302 d. Remembered unique code message This is also done to determine if it matches the issue. Therefore, the timing signal is input to the signal presence / absence determination section 302b.

 The signal presence / absence determination section 302b determines that a received signal of a predetermined level is received for a predetermined time after receiving the evening timing signal, and that the received unique code signal matches its own unique code signal. Then, the vehicle control means on the vehicle 3 side exists within a predetermined distance from the wireless key 1.

 However, even if there is a timing signal input and the unique code signal matches its own, if the signal level is lower than a predetermined level, the wireless key 1 and the vehicle 3 are separated by a certain distance or more.

 Based on such a determination, the signal presence / absence determination unit 302b outputs mutually opposite control signals when the wireless key 1 exists within a predetermined distance and when it does not exist. On the basis of the control signal from the signal presence / absence determining section 302 b, the open / close control signal generating section 303 outputs a door open / close control signal. Based on the door opening / closing control signal, the door is opened / closed in the vehicle 3 by a circuit (not shown).

 Here, in the above embodiment, it is assumed that a plurality of doors of the vehicle 3 are collectively controlled to be closed, but the application of the present invention is not limited to this. FIG. 14 shows an embodiment in which a plurality of drivers D1 to D5 are individually controlled using the wireless key 1 of the present invention.

 Antenna elements 301 to 300 of doors D1 to D5 corresponding to the common vehicle control means 300 mounted on the side of vehicle 3 are arranged. Therefore, bidirectional communication is performed with any of the antenna elements 301 to 305 closest to the wireless key 1. At this time, the identifier ID added to the base response transmission pulse shown in Fig. 5e includes the number of the corresponding door, and the target door to be controlled is specified. Industrial potential

As described above with reference to the drawings, an embodiment of the present invention provides a vehicle security system in which battery consumption in a vehicle and a wireless key is reduced according to the present invention. It is possible to provide a vehicle key having a wireless authentication function and a wireless authentication function applied thereto.

Claims

The scope of the claims  1. A wireless key that generates a key transmission pulse,  A vehicle control means provided on the vehicle side, for searching for the key transmission pulse at a predetermined cycle and performing predetermined control on the vehicle when authentication is established with the wireless key;  The wireless key includes: means for generating and transmitting a predetermined number of the key transmission pulses when there is vibration to the key body; and receiving an identification signal responsive to the key transmission pulse from the vehicle side; Means for adding an identification signal of the wireless key to the key transmission pulse and transmitting the identification signal to the vehicle when the identification signal matches a predetermined signal.  A vehicle security system characterized in that: 2. In Claim 1,  A vehicle security system, wherein a duty ratio between a time for searching for a key transmission pulse by the vehicle control means and a cycle for searching for the key transmission pulse is 1/10. 3. In claim 1,  The vehicle security system, wherein the vehicle control means enables predetermined control of the vehicle when the identification signal of the wireless key is a predetermined identification signal. 4. In Claim 3,  The vehicle security system is characterized in that the predetermined control for the vehicle is control for opening and closing a door of the vehicle. 5. In Claim 4, Further, the predetermined control for the vehicle includes a control for enabling or disabling engine starting of the vehicle. Tem 6. A wireless key which forms a vehicle security system with a vehicle provided with vehicle control means for searching for a key transmission pulse at a predetermined period and performing a predetermined control operation,  When there is vibration to the key body, a vibration sensor that turns on the key trigger and  Means for generating a predetermined number of key transmission pulses when the key trigger from the vibration sensor is on, and transmitting the key transmission pulses to the vehicle side;  An identification signal responsive to the key transmission pulse is received from the vehicle side, and when the identification signal matches a predetermined signal, the identification signal of the key body is added to the trigger pulse signal to be transmitted to the vehicle. Means to send  A wireless key characterized by having. 7. In Claim 6,  The power for driving the key body is supplied by a button battery. 8. In Claim 6,  A wireless key, wherein the vibration sensor comprises a mercury switch that is closed by the movement of a key holder. 9. In Claim 6,  The number of the key transmission pulses transmitted when the key trigger is turned on is set so that at least one key transmission pulse is detected within the time for searching for the key transmission pulse by the vehicle control means. A wireless key. 10. A wireless key that generates a key transmission pulse, A plurality of detection means for detecting the key transmission pulse provided on the vehicle side; and a key transmission pulse detected by any of the plurality of detection means provided on the vehicle side for a predetermined period. Vehicle authentication means for performing predetermined control on the vehicle when authentication with the key is established, wherein the wireless key transmits a predetermined number of the key transmission pulses when there is vibration to the key body. Means for generating and transmitting; and receiving an identification signal responsive to the key transmission pulse from the vehicle side, and when the identification signal matches a predetermined signal, converting the identification signal of the wireless key into the key transmission pulse. In addition, means for transmitting to the vehicle are provided.  A vehicle security system characterized in that: